cylinder wall too thin??

[Johnny123]

if i bore my block 40 over would their be a chance of it being to thin to maintain a boost of 20psi? that is my projected goal. when the motor work is done i still wont have the 16g i want, but eventually..do you think it would be too much?

 

[toofast82]

why do you need to bore it .040 over and not .020. I know .020 over will have no problem. Just curious why you would need to go that much? were the cylinders really messed up? you may want to source out another block

 

[RT-AWD]

.040 over is a lot my friend not sure why you would go that high unless you really needed to and even then i'd just get a new block.

 

[josh2ndgen]

I run +.40 block in my 2g so yes you can do it and yes it will hold 20psi. I run a gt42r on 36-40psi.

 

[crimsondragon]

You can bore up to .080 with no problems. Anymore than that, do at your own risk.

 

[Defiant]

I'd like backup for that .080 number. The maximum is .040, isn't it? Are you going Metric?

 

[B005T3D_1]

id have to agree, .080 seems a bit much... a good machine shop would be able to tell you the "safe" oversize for your motor, id go under that just to be sure. you can safely bore .020 without changing you internals i think up to .030 anything more than that and youll be pushing it, as far as not changing the pistons

 

[HIGHPSI4]

I bored my 4G64 (which is 1.5 mm or 0.060" over a 4G63) 0.040" over (87.5 mm). So, you should be good up to 0.080" over on a 4G63. Still running as of now...........

 

[crimsondragon]

Well I couldn't find the thread where somebody said .080 is still good. I did find this though.
http://www.dsmtuners.com/forums/cylinder-head-short-block/278926-0-50-over-bore.html